1.os

1 import os 2  3 # print(os.getcwd()) 4 # os.chdir("..") 5 # print(os.getcwd()) 6  7 # os.makedirs('dirname1/dirname2') 8 # os.removedirs("dirname1/dirname2") 9 # print(os.listdir())10 # print(os.stat("test.py"))11 12 # print(os.system("dir"))13 #14 # print(os.path.split(r"C:\Users\Administrator\脱产三期\day22\sss.py"))15 # print(os.path.dirname(r"C:\Users\Administrator\脱产三期\day22\sss.py"))16 # print(os.path.basename(r"C:\Users\Administrator\脱产三期\day22\sss.py"))17 a="C:\Users\Administrator"18 b="脱产三期\day22\sss.py"19 #20 os.path.join(a,b)#  路径拼接

2.xml解析

1 # import xml.etree.ElementTree as ET 2  3  4  5 # tree = ET.parse("../day22/xml_lesson.xml") 6 # root = tree.getroot() 7 # print(root.tag) 8  9 10 # for i in root:11 #12 #     # print(i.tag)13 #     # print(i.attrib)14 #     for j in i:15 #         # print(j.tag)16 #         # print(j.attrib)17 #         print(j.text)18 19 20 21 22 # # 遍历xml文档23 # for child in root:24 #     # print(child.tag, child.attrib)25 #     for i in child:26 #         print(i.tag, i.text)27 28 # 只遍历year 节点29 # for node in root.iter('year'):30 #     print(node.tag, node.text)31 # # ---------------------------------------32 33 # import xml.etree.ElementTree as ET34 #35 # tree = ET.parse("../day22/xml_lesson.xml")36 # root = tree.getroot()37 38 # 修改39 # for node in root.iter('year'):40 #     new_year = int(node.text) + 141 #     node.text = str(new_year)42 #     node.set("updated", "no")43 # #44 # tree.write("../day22/xml_lesson.xml")45 #46 # 删除node47 # for country in root.findall('country'):48 #     rank = int(country.find('rank').text)49 #     if rank > 50:50 #         root.remove(country)51 #52 # tree.write('output.xml')53 54 55 import xml.etree.ElementTree as ET56 57 new_xml = ET.Element("namelist")58 #59 name = ET.SubElement(new_xml, "name", attrib={
   "enrolled": "yes"})60 age = ET.SubElement(name, "age", attrib={
   "checked": "no"})61 sex = ET.SubElement(name, "sex")62 sex.text = '33'63 name2 = ET.SubElement(new_xml, "name", attrib={
   "enrolled": "no"})64 age = ET.SubElement(name2, "age")65 age.text = '19'66 67 68 69 et = ET.ElementTree(new_xml)  # 生成文档对象70 et.write("test1.xml", encoding="utf-8", xml_declaration=True)71 72 ET.dump(new_xml)  # 打印生成的格式

3.json & pickle

1 # dic='{"name":"alex"}' 2 # f=open("hello","w") 3 # f.write(dic) 4 # 5 # f_read=open("hello","r") 6 # data=f_read.read() 7 # print(type(data)) 8 # data=eval(data) 9 # print(data["name"])10 11 import json12 13 14 # dic={'name':'alex'}#---->{"name":"alex"}----->'{"name":"alex"}'15 # i=8                 #---->'8'16 # s='hello'          #---->"hello"------>'"hello"'17 # l=[11,22]           #---->"[11,22]"18 # #19 # f=open("new_hello","w")20 #21 # dic_str=json.dumps(dic)22 # f.write(dic_str)    #json.dump(dic,f)23 24 25 26 # f_read=open("new_hello","r")27 # data=json.loads(f_read.read())      # data=json.load(f)28 #29 # #30 # print(data["name"])31 # print(data)32 # print(type(data))33 34 # print(s)35 # print(type(s))36 37 38 # data=json.dumps(dic)39 40 # print(data)     #{"name": "alex"}41 # print(type(data))42 43 44 #注意：45 # import json46 #47 # with open("hello","r") as f:48 #     data=f.read()49 #     data=json.loads(data)50 #     print(data["name"])51 52 #----------------------pickle-------53 # import pickle54 55 # dic = {'name': 'alvin', 'age': 23, 'sex': 'male'}56 57 # print(type(dic))  # 
     
      58 #59 # j = pickle.dumps(dic)60 # print(type(j))  # 
      
       61 #62 # f = open('../day22/序列化对象_pickle', 'wb')  # 注意是w是写入str,wb是写入bytes,j是'bytes'63 # f.write(j)  # -------------------等价于pickle.dump(dic,f)64 #65 # f.close()66 # # -------------------------反序列化67 # import pickle68 #69 # f = open('../day22/序列化对象_pickle', 'rb')70 # #71 # data = pickle.loads(f.read())  # 等价于data=pickle.load(f)72 #73 # print(data['age'])74 # # -------------------------shelve模块---------75 import shelve76 #77 f = shelve.open(r'shelve1.bak')  # 目的：将一个字典放入文本 f={}78 #79 f['stu1_info']={
   'name':'alex','age':'18'}80 f['stu2_info']={
   'name':'alvin','age':'20'}81 f['school_info']={
   'website':'oldboyedu.com','city':'beijing'}82 f.close()83 84 print(f.get('stu1_info')['age'])85 86 87 88 # dic={}89 #90 # dic["name"]="alvin"91 # dic["info"]={"name":"alex"}
      
     

4.eval

1 print(eval("12+(34*6+2-5*(2-1))"))

5.sys

1 import sys 2 # # print(sys.argv) 3 # 4 # command=sys.argv[1] 5 # path=sys.argv[2] 6 # 7 # if command=="post": 8 #     pass 9 #10 # elif command=="get":11 #     pass12 #13 import time14 for i in range(100):15     sys.stdout.write("#")16     time.sleep(0.1)17     sys.stdout.flush()